[Selection of Laboratory Procedures to Detect Toxigenic by the 2-Step Method].

The 2-step method is an algorithm to detect toxigenic Clostridium difficile. We herein compared the sensitivities and specificities of an enzyme immunoassay (toxin A/B-EIA), toxigenic culture (TC-EIA), Loop-Mediated Isothermal Amplification assay (LAMP), and Xpert C. difficile (Xpert) with the detection of the toxin B gene by a polymerase chain reaction (PCR). The results obtained showed that the sensitivities and specificities of toxin A/B-EIA, Xpert, TC-EIA, and LAMP were 30 and 100%, 87.2 and 100%, 97.5 and 89.7%, and 95 and 100%, respectively. We also evaluated the turnaround time (TAT) and cost of toxigenic C. difficile detection. Our hospital TAT for toxin A/B-EIA and TC-EIA are 37 min and 5 days, respectively. We estimated the TAT of Xpert, LAMP, and PCR to be 105 min, 5 days, and 6 days, respectively. On the other hand, the cost to detect toxigenic C. difficile increased in the order of TC-EIA, LAMP, Xpert, and PCR. We have never experienced outbreak of Clostridium difficile infection (CDI) in our hospital, and there is less the number of CDI than other place. So we selected TC-EIA that is good sensitivity and low cost per specimen. Hereafter it'll be necessary to solve a problem it takes time, because we have to respond to outbreak of CDI quickly if it happens.

Multicenter retrospective study of cefmetazole and flomoxef for treatment of extended-spectrum-ß-lactamase-producing Escherichia coli bacteremia.

The efficacy of cefmetazole and flomoxef (CF) for the treatment of patients with extended-spectrum ß-lactamase-producing Escherichia coli (ESBL-EC) bacteremia (ESBL-CF group) was compared with that of carbapenem treatment for ESBL-EC patients (ESBL-carbapenem group) and with that of CF treatment in patients with non-ESBL-EC bacteremia (non-ESBL-CF group). Adult patients treated for E. coli bacteremia in four hospitals were retrospectively evaluated. The 30-day mortality rates in patients belonging to the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were compared as 2 (empirical and definitive therapy) cohorts. The adjusted hazard ratios (aHRs) for mortality were calculated using Cox regression models with weighting according to the inverse probability of propensity scores for receiving CF or carbapenem treatment. The empirical-therapy cohort included 104 patients (ESBL-CF, 26; ESBL-carbapenem, 45; non-ESBL-CF, 33), and the definitive-therapy cohort included 133 patients (ESBL-CF, 59; ESBL-carbapenem, 54; non-ESBL-CF, 20). The crude 30-day mortality rates for patients in the ESBL-CF, ESBL-carbapenem, and non-ESBL-CF groups were, respectively, 7.7%, 8.9%, and 3.0% in the empirical-therapy cohort and 5.1%, 9.3%, and 5.0% in the definitve-therapy cohort. In patients without hematological malignancy and neutropenia, CF treatment for ESBL-EC patients was not associated with mortality compared with carbapenem treatment (empirical-therapy cohort: aHR, 0.87; 95% confidence interval [CI], 0.11 to 6.52; definitive therapy cohort: aHR, 1.04; CI, 0.24 to 4.49). CF therapy may represent an effective alternative to carbapenem treatment for patients with ESBL-EC bacteremia for empirical and definitive therapy in adult patients who do not have hematological malignancy and neutropenia.

[Testicular Tumor in a Patient with Delta Thalassemia Complicated with Hereditary Persistence of Fetal Hemoglobin].

A 30s male was diagnosed as having the left testicular tumor in 2010. He received the anti-neoplastic chemotherapy, and could achieve the complete remission. But, he relapsed with solitary retroperitoneal lymph node swelling in 2012, and he was referred to our hospital. Laboratory examination on his admission showed the significant increase of fetal hemoglobin (HbF) up to 16.4%. But, neither anemia nor hemolysis was found at that time. Coexistence of therapy-related myeloid neoplasm or HbF production by metastatic lesion was not definite. Isoelectrofocusing of his hemolysate showed the faint HbA2 in addition to dense HbF band. Molecular analysis of his Hb gene revealed the homozygous (G)gamma-158 (C-T) together with homozygous delta-77(T-C). From these findings, he was diagnosed as having hereditary persistence of HbF (HPFH) and homozygous delta thalassemia. The precise incidence of such combined genetic variation has been unknown because the majority of such cases seem to show no significant clinical symptoms as our case. Whereas, it seems necessary to remind the possibility of such genetic variation when adult patients with various acquired diseases such as testicular tumor or hematologic malignancies show the elevated HbF level.

[Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2012].

The nationwide surveillance of antibacterial susceptibility to meropenem (MEPM) and other parenteral antibiotics against clinical isolates during 2012 in Japan was conducted. A total of 2985 strains including 955 strains of Gram-positive bacteria, 1782 strains of Gram-negative bacteria, and 248 strains of anaerobic bacteria obtained from 31 medical institutions were examined. The results were as follows; 1. MEPM was more active than the other carbapenem antibiotics tested against Gram-negative bacteria, especially against enterobacteriaceae and Haemophilus influenzae. MEPM was also active against most of the species tested in Gram-positive and anaerobic bacteria, except for multi-drug resistant strains including methicillin-resistant Staphylococcus aureus (MRSA). 2. Of all species tested, there were no species, which MIC90 of MEPM was more than 4-fold higher than those in our previous studies in 2009 or 2006. Therefore, the tendency to increase in antimicrobial resistance rates was not observed. 3. MEPM resistance against Pseudomonas aeruginosa was 17.8% (56/315 strains). Compared to our previous results, it was the lowest than that in 2006 and 2009. 4. Carbapenem-resistant Klebsiella pneumoniae, and multi-drug-resistant Acinetobacter species, which emerged in worldwide, were not observed. 5. The proportion of extended-spectrum beta-lactamase (ESBL) strains was 6.2% (59/951 strains) in enterobacteriaceae, which increased compared with that of our previous studies in 2009 or before. Whereas, the proportion of metallo-beta-lactamase strains was 1.6% (5/315 strains) in P. aeruginosa, which was stable. In conclusion, the results from this surveillance suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem for serious infections treatment at present, 17 years passed after available for commercial use in Japan.

[Practical approach to infection control and antimicrobial stewardship by medical technologists].

Since establishing an antimicrobial management team (AMT) in 2003, we have been promoting both appropriate diagnosis and treatment and improving the prognosis of hospitalized patients with infections. AMT is composed of 4 doctors, 2 nurses, 2 pharmacists and one medical technologist. AMT members meet twice a week and discuss patients with positive blood cultures, with prescribed anti-MRSA drugs and suspected infections. Antimicrobial prescription and clinical laboratory data are obtained from the database of electric medical records and microbiological data from the laboratory database system. The initial step in infection control and antimicrobial stewardship is an accurate diagnosis of infection. Clinical microbiology laboratories play a critical role in infection control and antimicrobial stewardship by reporting accurate and timely results of both bacterial identification and antimicrobial susceptibility tests. Medical technologists are required to develop better competency and proficiency about clinical microbiology in both infection control and antimicrobial stewardship.

[Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2009].

The antibacterial activity of meropenem (MEPM) and other parenteral antibiotics against clinical isolates of 2655 strains including 810 strains of Gram-positive bacteria, 1635 strains of Gram-negative bacteria, and 210 strains of anaerobic bacteria obtained from 30 medical institutions during 2009 was examined. The results were as follows; (1) MEPM was more active than the other carbapenem antibiotics tested against Gram-negative bacteria, especially against enterobacteriaceae and Haemophilus influenzae. MEPM was also active against most of the species tested in Gram-positive and anaerobic bacteria, except for multidrug resistant strains including methicillin-resistant Staphylococcus aureus (MRSA). (2) MEPM maintained potent and stable antibacterial activity against Pseudomonas aeruginosa. The proportion of MEPM-resistant strains to ciprofloxacin-resistant strains or imipenem-resistant strains were 53.1% and 58.0% respectively. (3) The proportion of extended-spectrum beta-lactamase (ESBL) strains was 3.1% (26 strains) in enterobacteriaceae. And the proportion of metallo-beta-lactamase strains was 2.0% (6 strains) in P. aeruginosa. (4) Of all species tested, there were no species except for Bacteroides fragilis group, which MIC90 of MEPM was more than 4-fold higher than those in our previous study. Therefore, there is almost no significant decrease in susceptibility of clinical isolates to meropenem. In conclusion, the results from this surveillance study suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem for serious infections treatment at present, 14 years passed after available for commercial use in Japan.

[Rapid diagnosis of catheter-related bloodstream infection using bioluminescence assay].

Rapid diagnosis of the central venous catheter-related bloodstream infection (CR-BSI) is especially crucial in critical care settings. In this study, we applied bioluminescence assay method (BA method) to measure the levels of ATP, as a representative of bacterial count of the catheter tip. The efficacy of BA method was evaluated in comparison with Brun-Buisson method (BB method), a commonly used, semi-quantitative microbiological culture technique. Significant differences were detected in the ATP levels by BA method, 177 [935] vs. 1337 [5198] RLU(median [interquartile range: IQR]) between BB-negative and BB-positive group (p = 0.012). The sensitivity/specificity for the detection of BB-positive results was 88.9%/68.8% and 100.0%/65.7%, if we set the cutoff value of BA method as 500 and 300 RLU, respectively. BA method, a less time-consuming technique, could become a useful option for the rapid screening for CR-BSI.

[Evaluation of MRSA rapid detection by real-time PCR directly from positive blood cultures].

Methicillin-resistant Staphylococcus aureus (MRSA), a well-known causative multidrug-resistant pathogen responsible for nosocomial and community-acquired infections, particularly in blood stream infection, often proves difficult and expensive to treat. Despite the need for rapid, accurate MRSA detection for treatment and infection control, conventional testing including culture, have sensitivity and turn-around time (TAT) problems. We evaluated BD GeneOhm MRSA Detection Kit rapid detection performance directly from positive blood culture using real-time PCR. The kit recognizes, a specific part of the staphylococcal cassette chromosome mec (SCCmec) gene, not a mecA gene. Compared to conventional culture in 138 samples with gram stains showing gram-positive cocci (GPC) clusters, the kit's sensitivity was 100%, specificity 97.3%, positive predictive value 90% and negative predictive value 100%. Three of the 27 MSSA isolates found was false-positive, indicating that the kit detected SCCmec/orfX region sequences lacking mecA. Coupled with direct tube coagulase testing to rapidly differentiate MRSA from methicillin-susceptible S. aureus (MSSA) could provide optimum treatment through appropriate antibiotic use. The kit thus appears to be useful in rapidly diagnosing MRSA from blood culture, improving the prognosis and reducing medical cost.

[Evaluation of the MRSA rapid detection assay (BD GeneOhm MRSA detection kit) by a real-time PCR].

Methicillin-resistant Staphylococcus aureus (MRSA) is well known to be a causative pathogen of skin and soft tissue or blood stream infections, and also to be a nosocomial drug-resistant bacteria in healthcare settings. Although a rapid and accurate detection of MRSA is indispensable for infection control, the conventional tests including culture method have some problems of sensitivity, procedure time, and so on. We evaluated the performance of the rapid detection assay of MRSA (BD GeneOhm MRSA Detection Kit) directly from specimens by a real-time PCR. The principle of this kit is characterized by recognizing not a mecA gene, but a specific part of SCCmec gene. Limits of detection of this method was 810 CFU/mL. Compared to the results of mecA PCR assay in 105 clinically isolated samples, the sensitivity, specificity, positive predictive value and negative predictive value were 100%, 97.4%, 98.5% and 100%, respectively. One of the 38 mecA negative isolates was found to be a positive result, this finding suggested that this method detect sequences of SCCmec/orfX region lacking of mecA. Because of the rapid turn-around time and the excellent negative predictive value, this method appears to be a useful tool for rapid diagnosis of MRSA.

[Establishment of a microbiology laboratory open 365 days a year and its impact].

The microbiology laboratory of our university hospital aims to provide accurate and rapid microbiological results and useful information for healthcare workers involved in both the treatment of infectious diseases and infection control. For this purpose, we have been running a microbiology laboratory open 365 days a year since 2005. Before starting this laboratory, we formulated both a precise procedural manual and educational program to increase the number of microbiological technologists from 4 to 8 persons and improve their skills. Moreover, we reviewed the reporting system. As a result, we could report positive blood cultures up to 1.4 days earlier than previously possible, and significantly improved the prognosis of MRSA bacteremia patients by the early treatment of anti-MRSA antimicrobials within 48 hours after positive blood culture. In addition, the rate of MRSA/Staphylococcus aureus decreased to 35.8%. It is essential for the treatment of infectious diseases and infection control to accept only appropriate specimens and report the results rapidly and accurately.

Optimized dosage and frequency of cefozopran for patients with febrile neutropenia based on population pharmacokinetic and pharmacodynamic analysis.

OBJECTIVES: To establish a cefozopran (a fourth-generation cephem) population pharmacokinetic model using patient data and use it to explore alternative dosage regimens that could optimize the currently used dosing regimen to achieve higher likelihood of pharmacodynamic exposure against pathogenic bacteria. METHODS: We conducted a prospective clinical trial of cefozopran for haematological patients with febrile neutropenia (FN). Twenty-two patients (30 episodes) were selected to receive intravenous cefozopran every 8 h on a daily basis. We gathered concentration data and performed the NONMEM program. The Monte Carlo simulation was performed to assess the pharmacodynamic exposure based on the population pharmacokinetics and MIC. RESULTS: The NONMEM program demonstrated that a two-compartment model provided a best fit for the data, that is, CL of 4.62 (L/h), V1 of 10.3 (L), Q of 4.47 (L/h), and V2 of 4.48 (L). On the basis of the Japanese national surveillance findings for Pseudomonas aeruginosa, methicillin-sensitive Staphylococcus aureus, coagulase-negative Staphylococcus, viridans group streptococci, Escherichia coli and Klebsiella pneumoniae, Monte Carlo simulation data showed that probability of target attainment(T>MIC = 70%) is 67% to 97% for dosing every 8 h, and 48% to 88% for dosing every 12 h. For the patients in whom the efficacy of cefozopran could be evaluated, 17 of 22 patients (77.2%) survived the episode of FN without requiring further antibacterial treatment. CONCLUSIONS: Our study proved that Monte Carlo simulation based on population pharmacokinetics can determine optimized dosage and method. The optimal regimen for this cephem was found to be three times daily.

[Current biosafety in clinical laboratories in Japan: report of questionnaires' data obtained from clinical laboratory personnel in Japan].

To determine the status of biosafety in clinical laboratories in Japan, we conducted a survey using questionnaires on the biosafety of laboratory personnel in 2004. We obtained data from 431 hospitals (response: 59.5%). Respondents were 301 institutions (70%) having biological safety cabinets (BSCs). BSCs were held in 78% of microbiological laboratories, 7.9% of genetic laboratories, 2.7% of histopathological laboratories, and 1% or less at other laboratories. A clean bench in examination rooms for acid-fast bacilli was applied at 20 hospitals. We found 28 cases of possible laboratory-associated tuberculosis infection, 25 of which were associated with lack of BSC. Other risk factors were immature skills and insufficiently skilled eguipment operation. The frequency of rupture accidents during specimen centrifugation was 67% in dealing with blood and 9.7% in collecting acid-fast bacilli. Half or more accidents were related to inadequate sample tube materials. Technologists were shown to be working on blood collection in many hospitals (75%), and 1,534 events of self-inflicted needle puncture developed in the last 5 years. These results suggest that biosafety systems are woefully lacking or inadequate in clinical laboratories in Japan and must be established at the earliest possible opportunity.

[Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2006].

The antibacterial activity of meropenem (MEPM) and other parenteral antibiotics against clinical isolates of 876 strains of Gram-positive bacteria, 1764 strains of Gram-negative bacteria, and 198 strains of anaerobic bacteria obtained from 30 medical institutions during 2006 was measured. The results were as follows; 1. MEPM was more active than the other carbapenem antibiotics tested against Gram-negative bacteria, especially against enterobacteriaceae and Haemophilus influenzae. MEPM was also active against most of the species tested in Gram-positive and anaerobic bacteria, except for multi-drug resistant strains including methicillin-resistant Staphylococcus aureus. 2. As for Pseudomonas aeruginosa, all of the MEPM-resistant strains were resistant to imipenem (IPM). MEPM showed low cross-resistant rate both againt IPM-resistant P. aeruginosa (41.8%) and ciprofloxacin-resistant P. aeruginosa (33.3%). 3. The proportion of extended-spectrum beta-lactamase (ESBL) strains was 4.3% (6 strains) in Escherichia coli, 1.1% (1 strain) in Citrobacter freundii, 21.7% (5 strains) in Citrobacter koseri, 3.1% (4 strains) in Klebsiella pneumoniae, 3.3% (3 strains) in Enterobacter cloacae, 0.8% (1 strain) in Serratia marcescens, and 4.9% (2 strains) in Providencia spp. The proportion of metallo-beta-lactamase strains was 3.1% (10 strains) in P. aeruginosa. 4. Of all species tested, there were no species, which MIC90 of MEPM was more than 4-fold higher than those in our previous study. Therefore, there is almost no significant decrease in susceptibility of clinical isolates to meropenem. In conclusion, the results from this surveillance study suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem at present, 11 years after available for commercial use.

[Microbiology laboratory as a base of information sending].

The goal of our microbiology laboratory is to provide an accurate microbiological result and a useful information for every healthcare workers (HCWs). For this purpose, we were trying to do several activities, such as improving the work-flow of microbiology testings, starting 365-day-open microbiology tests, providing some training courses of microbiology and sending many useful informations about infectious diseases and infection control. Before these activities, we needed another 5 microbiology technicians beside 3 technicians and had started the program to educate them. We have successfully finished it and enabled all plans begin in April, 2005. Since then we are open for 365 days and also sending HCWs many newsletters for performing effective microbiological testings via the intra-network system and having lectures for both doctors and nurses, especially for new resident doctors at the orientation. We had also the training course for certified infection control nurses and accepted two technicians from Africa, who came to study a basic microbiology via JICA. These activities have enabled every technician not only to report and analyze microbiological test result effectively but also to improve writing and presentation skills. Through these activities all technicians have realized that accurate and rapid information from a microbiology laboratory is a key to treat patients with infectious diseases and improve their prognosis. It is suggested that skill-up of technicians lead to report an accurate result in microbiology and at the same time improve the attitude for their job.

Homogeneous Assays for LDL-C and HDL-C are Reliable in Both the Postprandial and Fasting State.

AIM: Most epidemiological and clinical studies calculated low-density lipoprotein-cholesterol (LDL-C) by Friedewald's formula which cannot be used in the postprandial samples. Although the homogeneous assays with poor analytical performance were withdrawn from the market, it remained unclear whether the currently available reagents for LDL-C and high-density lipoprotein-cholesterol (HDL-C) are as accurate for postprandial samples as for fasting samples. METHODS: Fresh blood samples were collected from 59 non-diseased and 109 diseased subjects. Postprandial samples constituted 72.9% and 39.4% of these samples. LDL-C and HDL-C concentrations were measured using the homogeneous assays of four manufacturers (Denka Seiken, Wako, Kyowa Medex, and Sekisui Medical). Simultaneously, LDL-C and HDL-C concentrations were determined using the reference measurement procedures (RMPs) of the Centers for Disease Control and Prevention (CDC). Total errors were calculated using a routine method (TEcom) and via error component analysis (TEECA). RESULTS: All homogeneous assays for LDL-C and HDL-C met the National Cholesterol Education Program (NCEP) requirements in terms of coefficient of variation, and TEcom in both non-diseased and diseased subjects. LDL-C and HDL-C values measured by the homogeneous assays were in good agreement with those measured by the RMPs in both fasting and postprandial samples. The TEcom and TEECA values of the postprandial samples were similar to those of fasting samples, although the TEECA values were up to 4.4-fold greater than the TEcom values. CONCLUSIONS: In both non-diseased and diseased subjects, the homogeneous assays for LDL-C and HDL-C of four manufacturers are as accurate for postprandial samples as for fasting samples.

Impact of industrial structure and soil exposure on the regional variations in pulmonary nontuberculous mycobacterial disease prevalence.

OBJECTIVE/BACKGROUND: The prevalence of pulmonary nontuberculous mycobacterial (pNTM) disease, including Mycobacterium avium complex (MAC), varies widely according to geographic region. However, the factors that influence regional variations in pNTM disease prevalence remain unknown. This study was undertaken to examine whether environmental or occupational factors or host traits could influence regional variations in pNTM disease prevalence. METHODS: We collected laboratory data on pulmonary tuberculosis (pTB) and pNTM from two hospitals in the West Harima area of Japan and five hospitals in Kyoto City, Japan from 2012 to 2013. We estimated microbiological pNTM disease prevalence by multiplying all pTB cases in each area with the ratio of pNTM cases and pTB cases at the survey hospitals in each area. We administered a standardized questionnaire to 52 patients and 120 patients with pulmonary MAC (pMAC) disease at Ako City Hospital and Kyoto University Hospital, respectively. RESULTS: The estimated prevalence of microbiological pNTM disease in the West Harima area (85.4/100,000 population-years) was significantly higher than that observed in Kyoto City (23.6/100,000 population-years; p<.001). According to multiple logistic regression analysis, in Ako City Hospital, primary (activities directly related to natural resources) and secondary industries (construction, mining, and manufacturing primary industry produce; odds ratio [OR]=4.79; 95% confidence interval [CI]=1.49-14.0; p=.007) and soil exposure (OR=13.6; 95% CI=4.94-45.26; p<.001) were associated with pMAC disease. CONCLUSION: Environmental factors, both industrial structures associated with occupational dust and environmental soil exposure, could influence the regional variations in pNTM disease prevalence.

[Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2004].

The antibacterial activity of meropenem (MEPM) and other parenteral antibiotics against clinical isolates of 907 strains of Gram-positive bacteria, 1790 strains of Gram-negative bacteria, and 192 strains of anaerobic bacteria obtained from 30 medical institutions during 2004 was measured. The results were as follows; 1. MIC90 of MEPM for almost all of enterobacteriaceae and Haemophilus influenzae were 4-fold to 32-fold lower than those of other carbapenems. MEPM was more active than other carbapenem antibiotics against Gram-negative bacteria, especially against enterobacteriaceae and H. influenzae. MEPM were active against most of the species tested in Gram-positive and anaerobic bacteria, except for multi-drug resistant strains including methicillin-resistant Staphylococcus aureus. 2. As for Pseudomonas aeruginosa, imipenem (IPM) showed high cross-resistant rate againt meropenem-resistant P. aeruginosa (87.9%). MEPM showed low cross-resistant rate both againt IPM-resistant P. aeruginosa (49.2%) and ciprofloxacin-resistant P. aeruginosa (38.0%). 3. The proportion of extended-spectrum beta-lactamase (ESBL) strains was 3.1% (4 strains) in Escherichia coli, 8.0% (2 strains) in Citrobacter koseri, 2.5% (3 strains) in Klebsiella pneumoniae, 2.5% (2 strains) in Enterobacter cloacae, 0.9% (1 strains) in Serratia marcescens, and 2.2% (2 strains) in Proteus mirabilis. The proportion of metallo-beta-lactamase strains was 1.6% (5 strains) in P. aeruginosa. 4. Of all species tested, Peptostreptococcus spp. was the only species, which MIC90 of MEPM was more than 4-fold higher than that in our previous study using clinical isolates during 2002 (0.25 microg/ml --> 1 microg/ml). Therefore, there is almost no siginificant decrease in susceptibility of clinical isolates to meropenem. In conclusion, the results from this surveillance study suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem at present, 9 years after available for commercial use.

[Nationwide surveillance of parenteral antibiotics containing meropenem activities against clinically isolated strains in 2002].

The antibacterial activity of meropenem (MEPM) and other parenteral antibiotics against clinical isolates of 899 strains of Gram-positive bacteria, 1500 strains of Gram-negative bacteria, and 158 strains of anaerobic bacteria obtained from 28 medical institutions during 2002 was measured. The results were as follows; 1. MEPM was more active than other carbapenem antibiotics against Gram-negative bacteria, especially against enterobacteriaceae and Haemophilus influenzae. MIC90 of MEPM against Pseudomonas aeruginosa was the lowest of the drugs tested. MEPM showed low cross-resistant rate against both imipenem-resistant P. aeruginosa and ciprofloxacin-resistant P. aeruginosa. MEPM was active against most of the species tested in Gram-positive and anaerobic bacteria, except for multi-drug resistant strains including methicillin-resistant Staphylococcus aureus (MRSA), methicillin-resistant Staphylococcus epidermidis (MRSE). 2. The proportion of extended-spectrum beta-lactamase (ESBL) strains was 3.1% (4 strains) in Escherichia coli and 1.9% (2 strains) in Klebsiella pneumoniae. Carbapenems including MEPM were active against these ESBL strains. In conclusion, the results from this surveillance study suggest that MEPM retains its potent and broad antibacterial activity and therefore is a clinically useful carbapenem; at present, 7 years after available for commercial use.

[Detection of drug resistant bacteria and correspondence of microbiological laboratory to clinical physicians].

The world is now being faced with the battle for antimicrobial resistant organisms(ARO), such as MRSA, PRSP, ESBL producing GNR, MDRP and VRSA. These AROs are causing hospital-acquired infections(HAI) by the way of person-to-person transmission. The role of microbiological laboratories in hospitals is quite important in controlling HAI. Firstly, accurate detection of AROs is essential. They have to be proficient in both isolation and detection of AROs. Secondly, they have to return the results rapidly for not only clinicians but infection control team(ICT) to prevent more spread of HAI if an isolated organism is ARO. Thirdly, they have to report the statistical data about isolated organisms for ICT in each hospital. AROs can be isolated by three major methods, detection of responsible resistant genes or proteins and antimicrobial susceptibility tests. Most laboratories isolate AROs, using one or two of these methods. They should be prepared for and follow the most current criteria of AROs by Japanese original standard, or presented from NCCLS. Microbiological laboratories should also play a role in both hospital epidemiology and appropriate antimicrobial use by providing useful information, annual or periodical reports of antimicrobial susceptibility for isolated organisms which are relevant in their hospital. The microbiological laboratory which have good skills in detecting AROs, analyzing epidemiological data and communicating with all hospital workers, is now required from ICT in controlling HAI.

Prevalence of plasmid-mediated AmpC ß-lactamase-producing Escherichia coli and spread of the ST131 clone among extended-spectrum ß-lactamase-producing E. coli in Japan.

In 2010, a total of 1327 clinical Escherichia coli isolates from five hospitals in the Kyoto and Shiga regions of Japan were analysed by PCR. The prevalences of plasmid-mediated AmpC ß-lactamase (pAmpC)-producers, extended-spectrum ß-lactamase (ESBL)-producers and co-producers of pAmpC and ESBL were 1.7%, 9.7% and 0.3%, respectively. Less than one-half of the pAmpC-producers were reported to be resistant to third-generation cephalosporins, cephamycins and ß-lactam/ß-lactam inhibitors using the old 2009 Clinical and Laboratory Standards Institute (CLSI) breakpoints. CMY-2 was the most prevalent pAmpC type (95%), and CTX-M-14 (38%), CTX-M-15 (26%) and CTX-M-27 (19%) were the most prevalent ESBL types. The worldwide O25b-ST131-B2 clone accounted for 11% of pAmpC-producers and 41% of ESBL-producers. The O25b-ST131-B2 clone was characterised by a CTX-M-27- or CTX-M-15-type ESBL and ciprofloxacin-non-susceptibility with quadruple mutations in the quinolone resistance-determining regions (S83L and D87N in GyrA and S80I and E84V in ParC). A significant proportion of pAmpC-producers and the O25b-ST131-B2 clone were found in Japan by a recent regional surveillance programme.